The principal aim of this monograph is to acquaint the scientific community and the general public, as well as members of various government agencies, with information documenting: the current environmental radiation levels at the test site and in its test areas; the scope of activities to clean up the nuclear testing infrastructure and aftermath of the closure of adits and to clean up vertical shafts and ICBM launch silos; the scale and levels of radioactive contamination of the Semipalatinsk region; current source data for possible establishment of a database of various radiation parameters needed for making decisions relating to the transfer of the grounds of the former nuclear test site to civilian use. An objective assessment of the results of the Semipalatinsk Test Sites operation is impossible without exploring the historical phases of its creation, the conduct of nuclear tests, and conversion. In this monograph, we present the most important facts that have affected the test sites operation and the consequences of that operation.